1. Field of the Invention
This invention pertains to pressurized fluid spraying systems, and more particularly to a handheld paint spraying apparatus having anti-sputter valve components that stop the flow of fluid through the nozzle when the pressure of the fluid drops below an adjustable threshold level.
2. Description of Related Art
Painting architectural structures can be an extremely labor and time intensive activity. The fees charged for painting the interior or exterior of a building, for example, are based primarily on the time it takes a painter to complete the project as well as the cost of materials. Accordingly, it is beneficial to increase a painter's efficiency so as to reduce the overall time spent on a project by the painter and thereby reduce the labor costs of a project.
One conventional approach to painting walls or structures has been to use a paintbrush. However, the brush approach can be prohibitively expensive, especially if the structure has a large surface area for the painter to paint. To complete the task with a paintbrush, the painter is required to use many repetitive strokes, and the brush has to be continually rewetted after the paint is applied to the surface. In addition, the amount of surface area that can be covered by a given stroke of the paintbrush is limited to the width of the brush.
Another conventional approach, which is an improvement over using a paintbrush, is using a paint roller. In most aspects, using a paint roller is similar to using a paint brush (i.e. repetitive strokes and continual rewetting); however, the main advantage that a paint roller has over a paint brush is that the roller's width is generally greater than that of a paint brush, thus allowing the painter to cover more surface area with a given stroke.
A painter's application efficiency when using a paint roller was improved by the introduction of rollers with a pressurized paint supply feeding the roller mechanism through a tube. The pressurized paint supply in these devices eliminated the need to continually rewet the roller, thus saving valuable time. However, the amount of surface area that can be painted with any given stroke of the roller is still limited by the width of the roller.
Paint sprayers were developed as an improvement over the pressurized roller approach and have a substantially larger covering stroke than the roller. A paint sprayer allows a painter to paint a significantly larger surface area in less time than with a pressurized roller, particularly when painting large wall or ceiling areas that require an even, uniform coating of paint. Note, however, that defects and an uneven application of paint will be particularly noticeable on long walls and ceilings. Therefore, one disadvantage associated with the use of paint sprayers is that a less than uniform coat of paint may often be applied to the surface by any single pass of the sprayer. The painter is required to hold the spray nozzle, aim it at the surface to be painted, and physically move the spray nozzle along the front of the surface, usually back and forth vertically or horizontally. If the painter varies the pace at which the spray nozzle moves across the surface, varies the distance of the nozzle from the surface or varies the angle of the nozzle relative to the surface, a non-uniform coat of paint may result. This condition requires the painter to spray the surface with another coat until a uniform coat is achieved. In addition to wasting time, this repetitive process also wastes paint, and unnecessarily adds to the expense of completing the project.
Another significant disadvantage demonstrated by some single and multiple nozzle sprayers is that the paint may sputter or spurt from the nozzle after the source of pressurized paint has been shut off due to residual pressure in the system. Similar problems of excess fluid escaping the nozzles are also experienced with other pressurized fluid spraying systems used in manufacturing industries and the like. When the pressure in the system and the distance between the control valve and the nozzle increase, the amount of sputtering experienced by the sprayer increases. Sputtering creates defects in the painted surface that must be removed and/or repainted.
Spraying devices with banks of anti-sputter spray nozzles have been developed to improve the application time and consistency of the layers of applied paint. For example, U.S. Pat. No. 5,935,657, incorporated herein by reference, describes a multiple nozzle paint spraying system mounted to a portable stand that permits the moving the system along a floor surface for painting large wall and ceiling areas. However, the device is not adapted for handheld use.
Accordingly, there is a need for a handheld paint spraying system that allows a painter to work more efficiently by applying paint quickly and uniformly without sputtering, thereby allowing the painter to save time, effort and paint. The present invention satisfies those needs, as well as others, and generally overcomes the deficiencies found in the background art.